Active substances for increasing the stress defense in plants to abiotic stress, and methods of finding them

ABSTRACT

The invention relates to a method of finding compounds which increase the tolerance of plants to abiotic stress factors acting on this plant, such as, for example, temperature (such as chill, frost or heat), water (such as dryness, drought or anoxia), or the chemical load (such as lack of or excess of mineral salts, heavy metals, gaseous noxious substances) by increasing the expression of plant-endogenous proteins, and to the use of these compounds for increasing the tolerance in plants to abiotic stress factors.

The invention relates to a method of finding compounds which increasethe tolerance of plants to abiotic stress factors acting on this plant,such as, for example, temperature (such as chill, frost or heat), water(such as dryness, drought or anoxia), or the chemical load (such as lackof or excess of mineral salts, heavy metals, gaseous noxious substances)by increasing the expression of plant-endogenous proteins, and to theuse of these compounds for increasing the stress defense in plants toabiotic stress factors.

It is known that plants react with specific or unspecific defensemechanisms to natural stress conditions, such as, for example, chill,heat, drought, wounding, pathogen attack (viruses, bacteria, fungi,insects) and the like, but also to herbicides [Pflanzenbiochemie, pp.393-462, Spektrum Akademischer Verlag, Heidelberg, Berlin, Oxford, HansW. Heldt, 1996; Biochemistry and Molecular Biology of Plants, pp.1102-1203, American Society of Plant Physiologists, Rockville, Md., eds.Buchanan, Gruissem, Jones, 2000].

In plants, there are known a large number of proteins and the genesencoding them which are involved in defense reactions against abioticstress (for example chill, heat, drought, salt). Some of them belong tosignal transduction chains (for example transcription factors, kinases,phosphatases) or they bring about a physiological response of the plantcell (for example ion transport, detoxification of reactive oxygenspecies). The signal chain genes of the abiotic stress reaction include,inter alia, transcription factors of classes DREB and CBF (Jaglo-Ottosenet al., 1998, Science 280: 104-106). Phosphatases of the ATPK and MP2Ctype are involved in the salt stress reaction. Furthermore, salt stressfrequently activates the biosynthesis of osmolytes such as proline orsucrose. Sucrose synthase and proline transporters (Hasegawa et al.,2000, Annu Rev Plant Physiol Plant Mol Biol 51: 463-499) are examples ofthose which are involved here. The stress defense of plants to chill anddrought utilizes in some cases the same molecular mechanisms. Theaccumulation of what are known as late embryogenesis abundant proteins(LEA proteins), which include the dehydrins as important class (Ingramand Bartels, 1996, Annu Rev Plant Physiol Plant Mol Biol 47: 277-403,Close, 1997, Physiol Plant 100: 291-296), is known. These are chaperoneswhich stabilize the vesicles, proteins and membrane structures instressed plants (Bray, 1993, Plant Physiol 103: 1035-1040). Moreover,aldehyde dehydrogenases, which detoxify the reactive oxygen species(ROSs) which are generated as the result of oxidative stress, are,moreover, frequently induced (Kirch et al., 2005, Plant Mol Biol 57:315-332).

Heat shock factors (HSFs) and heat shock proteins (HSPs) are activatedunder heat stress conditions and as chaperones play a similar role tothe dehydrins in the case of chill and drought stress (Yu et al., 2005,Mol Cells 19: 328-333).

Most of the molecular mechanisms described are activated by geneexpression being induced. This results in the interesting possibility ofcharacterizing specific stress responses of plants with the aid oftranscriptome analysis, for example by gene expression profiling (GEP),with DNA microarrays or with comparable techniques (Rensink et al.,2005, Genome 48: 598-605, Cheong et al., 2002, Plant Physiology 129:661-677). In this manner, specific stress-reactive gene expressionpatterns can be recorded and compared with one another.

It is furthermore known that chemical substances can increase thetolerance of plants to abiotic stress. Such substances are appliedeither by seed dressing, by foliar application or by soil treatment.Thus, increasing the abiotic stress tolerance of crop plants bytreatment with elicitors of the systemic acquired resistance (SAR) orwith abscisic acid derivatives has been described (Schading and Wei,WO-200028055, Abrams and Gusta, U.S. Pat. No. 5,201,931, Churchill etal., 1998, Plant Growth Regul 25: 35-45).

When applying fungicides, in particular from the strobilurin group,similar effects are also observed, and these frequently also entailincreased yields (Draber et al., DE-3534948, Bartlett et al., 2002, PestManag Sci 60: 309).

Moreover, there have been described effects of growth regulators on thestress tolerance of crop plants (Morrison and Andrews, 1992, J PlantGrowth Regul 11: 113-117, RD-259027). In the case of osmotic stress, aprotective effect as the result of the application of osmolytes such as,for example, glycin betaine or their biochemical precursors, for examplecholine derivatives, has been observed (Chen et al., 2000, Plant CellEnviron 23: 609-618, Bergmann et al., DE-4103253). The effect ofantioxidants such as, for example, naphthols and xanthins for increasingthe abiotic stress tolerance in plants has also already been described(Bergmann et al., DD-277832, Bergmann et al., DD-277835). However, themolecular causes of the anti-stress effect of the substances are largelyunknown.

Thus, it is known that plants have available a plurality of endogenousreaction mechanisms which can bring about an effective defense to a widerange of harmful organisms and/or natural abiotic stress. However, aprediction as to which defense reactions could be provoked or modulatedin a targeted fashion by applying active substances was hithertounknown.

There is therefore a need for a method for the targeted finding ofmolecular activators of plant-endogenous defense mechanisms to abioticstress (such as, for example, heat, chill, drought, salinity and acidand base load), whereby novel active substances can be found, novelproperties of known, but differently acting, active substances can beidentified, or else known molecules or lead structures can be optimizedfor the use as inductors of the plant-endogenous defense mechanisms toabiotic stress factors.

Definitions of Terms Used Hereinbelow

The term “BLAST analyses” (Blast=Basic Local Alignment Search Tool)” asused herein describes the use of suitable computer programs for theclassification and finding of potentially homologous sequences (Altschulet al., J. Mol. Biol. 1990, 215: 403-410), where an alignment is madebetween a query sequence and all sequences in one or more databases withspecification of a desired agreement in the form of a scoring function(R. Rauhut, Bioinformatik, pp. 38-107, Verlag Wiley-VCH Verlag GmbH,Weinheim, 2001).

The term “cDNA” (complementary DNA) as used in the present contextdescribes a single DNA strand which is complementary to an RNA and whichis synthetized in vitro by an enzymatic reverse transcription. The cDNAcan correspond either to the total length of the RNA or else onlyconstitute a partial-sequence of the RNA which acts as template.

The term “cluster analysis” as used in the present context means thesummary of the individual data obtained by means of a computer programdeveloped for this purpose, where groups of genes which code forproteins with a similar function, or else genes with a similarexpression pattern, are shown in a conclusive fashion. This results in ahierarchic minimization of the complex data pattern which can be shownin the form of a dendrogram. The cluster analysis makes possible theclassifying assessment of the data sets obtained, which markedly exceedsa mere accumulation of unrelated data.

The terms “DNA chip” and “DNA microarray”, which are used synonymouslyin this context, refer to a support whose matrix consists for example ofglass or nylon and whose matrix has DNA fragments fixed to it, where theattachment of the DNA can be effected for example by (a) aphotolithographic method (DNA is synthetized directly on the support ofthe array), (b) a microspotting method (extraneously synthesizedoligonucleotides or PCR products are applied to the support and boundedcovalently), or (c) by a microspraying method (extraneously synthesizedoligonucleotides or PCR products are sprayed onto the support withouttouching, using an ink-jet printer) (R. Rauhut, Bioinformatik, pp.197-199, Verlag Wiley-VCH Verlag GmbH, Weinheim, 2001). A DNA chip whichrepresents genomic sequences of an organism is referred to as a “genomicDNA chip”. The evaluation of the data obtained with these “DNA chips” isreferred to as “DNA chip analysis”.

The term “DNA chip hybridization” as used in the present context meansthe pairing of two single-stranded, complementary nucleic acidmolecules, where one of the base-pairing molecule partners is located onthe DNA chip as DNA (deoxyribonucleic acid) in preferably covalentlybonded form, while the other is in solution in the form of the RNA(ribonucleic acid) or the corresponding cDNA (complementary DNA). Thehybridization of the bonded and unbonded nucleic acids on the DNA chiptakes place in aqueous buffer solution, if appropriate underadditionally denaturing conditions such as, for example, in the presenceof dimethyl sulfoxide, at temperatures of 30-60° C., preferably 40-50°C., especially preferably at 45° C. for 10-20 hours, preferably for14-18 hours, especially preferably for 16 hours, with constant movement.The hybridization conditions can be established in a constant fashionfor example in a hybridization oven. Standard movements of 60 rpm(rounds per minute, revolutions per minute) are produced in such ahybridization oven.

The nucleic acid sequence referred to by the term “EST sequence”(expressed sequence tag) means, in the present context, a short sequenceof 200-500 bases or base pairs.

The terms “expression pattern”, “induction pattern” and “expressionprofile”, which are used synonymously describe, in the present context,the expression differentiated over time and/or the tissue-specificexpression of the plant mRNA, the pattern being obtained directly by thegenerated intensity of the hybridization signal of the RNA obtained fromthe plant or its corresponding cDNA with the aid of the DNA chiptechnology. The measured “induction values” are obtained by directnumerical processing with the corresponding signals which are obtainedby using a synonymous chip, with the hybridization with anuntreated/stressed control plant.

The term “expression state” which is obtained by the “gene expressionprofiling” which has been carried out describes, in the present context,all of the recorded transcriptional activity of cellular genes which ismeasured with the aid of a DNA chip.

The term “total RNA” as used in the present context describes therepresentation, which is possible as the result of the disruption methodapplied, of different plant-endogenous RNA groups which can be presentin a plant cell, such as, for example, cytoplasmic rRNA (ribosomal RNA),cytoplasmic tRNA (transfer RNA), cytoplasmic mRNA (messenger RNA) andtheir respective nuclear precursors, ctRNA (chloroplastidial RNA) andmtRNA (mitochondrial RNA), but it also comprises RNA molecules which canbe obtained from exogenous organisms, such as, for example, viruses, orfrom parasitic bacteria and fungi.

The term “useful plants” means, in the present context, crop plantswhich are employed as plants for obtaining foodstuffs, feed stuffs orfor industrial purposes.

The term “safener” as used in the present context refers to a chemicalcompound which is of non-plant-endogenous origin and which compensatesfor, or reduces, the phytotoxic properties of a pesticide in relation touseful plants, without substantially reducing the pesticidal activity inrelation to harmful organisms such as, for example, weeds, bacteria,viruses and fungi.

Safeners which, in addition to their function for which they are knownper se, also contribute to increasing the tolerance to abiotic stressfactors are preferably selected from the group defined hereinbelow, itbeing possible to select different safeners depending on the abioticstress factor, and it being possible to use only a single safener orelse a plurality of safeners from the same group or from differentgroups:

-   a) compounds of the formulae (I) to (III),    where the symbols and indices have the following meanings:-   n′ is is a natural number from 0 to 5, preferably 0 to 3;-   T is a (C₁ or C₂)alkanediyl chain which is unsubstituted or    substituted by one or two (C₁-C₄)alkyl radicals or with    [(C₁-C₃)alkoxy]carbonyl;-   W is an unsubstituted or substituted divalent heterocyclic radical    selected from the group of the partially unsaturated or aromatic    five-membered heterocycles with 1 to 3 hetero ring atoms of the N or    O type, where the ring contains at least one nitrogen atom and not    more than one oxygen atom, preferably a radical selected from the    group (W1) to (W4),-   m′ is or 0 or 1;-   R¹⁷, R¹⁹ are identical or different and are halogen, (C₁-C₄)alkyl,    (C₁-C₄)alkoxy, nitro or (C₁-C₄)haloalkyl;-   R¹⁸, R²⁰ are identical or different and are OR²⁴, SR²⁴ or NR²⁴R²⁵ or    a saturated or unsaturated 3- to 7-membered heterocycle having at    least one nitrogen atom and up to 3 heteroatoms, preferably selected    from the group consisting of O and S, which heterocycle is linked    with the carbonyl group (II) or (III) via the nitrogen atom and is    unsubstituted or substituted by radicals selected from the group    consisting of (C₁-C₄)alkyl, (C₁-C₄)alkoxy or optionally substituted    phenyl, preferably a radical of the formula OR²⁴, NHR²⁵ or N(CH₃)₂,    in particular of the formula OR²⁴;-   R²⁴ is hydrogen or an unsubstituted or substituted aliphatic    hydrocarbon radical, preferably having a total of 1 to 18 carbon    atoms;-   R²⁵ is halogen, (C₁-C₆)alkyl, (C₁-C₆)alkoxy or substituted or    unsubstituted phenyl;-   R^(X) is H, (C₁-C₈)alkyl, C₁-C₈(haloalkyl),    (C₁-C₄)alkoxy(C₁-C₈)alkyl, cyano or COOR²⁶, where R²⁶ is hydrogen,    (C₁-C₈)alkyl, (C₁-C₈)haloalkyl, (C₁-C₄)alkoxy-(C₁-C₄)alkyl,    (C₁-C₆)hydroxyalkyl, (C₃-C₁₂)cycloalkyl or tri(C₁-C₄)alkylsilyl;-   R²⁷, R²⁸, R²⁹ are identical or different and are hydrogen,    (C₁-C₈)alkyl, (C₁-C₈)haloalkyl, (C₃-C₁₂)cycloalkyl or substituted or    unsubstituted phenyl;-   R²¹ is (C₁-C₄)alkyl, (C₁-C₄)haloalkyl, (C₂-C₄)alkenyl,    (C₂-C₄)haloalkenyl, (C₃-C₇)cycloalkyl, preferably dichloromethyl;-   R²², R²³ are identical or different and are hydrogen, (C₁-C₄)alkyl,    (C₂-C₄)alkenyl, (C₂-C₄)alkynyl, (C₁-C₄)haloalkyl,    (C₂-C₄)haloalkenyl, (C₁-C₄)alkylcarbamoyl-(C₁-C₄)alkyl,    (C₂-C₄)alkenylcarbamoyl(C₁-C₄)alkyl, (C₁-C₄)alkoxy-(C₁-C₄)alkyl,    dioxolanyl(C₁-C₄)alkyl, thiazolyl, furyl, furylalkyl, thienyl,    piperidyl, substituted or unsubstituted phenyl, or R²² and R²³    together form a substituted or unsubstituted heterocyclic ring,    preferably an oxazolidine, thiazolidine, piperidine, morpholine,    hexahydropyrimidine or benzoxazine ring;-   b) one or more compounds from the group consisting of:-   1,8-naphthalic anhydride,-   methyldiphenyl methoxyacetate,-   1-(2-chlorobenzyl)-3-(1-methyl-1-phenylethyl)urea (cumyluron),-   O,O-diethyl S-2-ethylthioethyl phosphorodithioate (disulfoton),-   4-chlorophenyl methylcarbamate (mephenate),-   O,O-diethyl O-phenyl phosphorothioate (dietholate),-   4-carboxy-3,4-dihydro-2H-1-benzopyran-4-acetic acid (CL-304415,    CAS-Reg. No: 31541-57-8),-   cyanomethoxyimino(phenyl)acetonitrile (cyometrinil),-   1,3-dioxolan-2-ylmethoxyimino(phenyl)acetonitrile (oxabetrinil),-   4′-chloro-2,2,2-trifluoroacetophenone O-1,3-dioxolan-2-ylmethyloxime    (fluxofenim),-   4,6-dichloro-2-phenylpyrimidine (fenclorim),-   benzyl 2-chloro-4-trifluoromethyl-1,3-thiazole-5-carboxylate    (flurazole),-   2-dichloromethyl-2-methyl-1,3-dioxolane (MG-191),-   N-(4-methylphenyl)-N′-(1-methyl-1-phenylethyl)urea (dymron),-   (2,4-dichlorophenoxy)acetic acid (2,4-D),-   (4-chlorophenoxy)acetic acid,-   (R,S)-2-(4-chloro-o-tolyloxy)propionic acid (mecoprop),-   4-(2,4-dichlorophenoxy)butyric acid (2,4-DB),-   (4-chloro-o-tolyloxy)acetic acid (MCPA),-   4-(4-chloro-o-tolyloxy)butyric acid,-   4-(4-chlorophenoxy)butyric acid,-   3,6-dichloro-2-methoxybenzoic acid (dicamba),-   1-(ethoxycarbonyl)ethyl 3,6-dichloro-2-methoxybenzoate    (lactidichlor)-   and their salts and esters, preferably (C₁-C₈);-   c) N-acylsulfonamides of the formula (IV) and their salts,    in which-   R³⁰ is hydrogen, a hydrocarbon radical, an oxyhydrocarbon radical, a    thiohydrocarbon radical or a heterocyclyl radical which is    preferably bonded via a carbon atom, for each of the last-mentioned    4 radicals is unsubstituted or substituted by one or more identical    or different radicals selected from the group consisting of halogen,    cyano, nitro, amino, hydroxyl, carboxyl, formyl, carboxamide,    sulfonamide and radicals of the formula -Z^(a)-R^(a), where each    hydrocarbon moiety preferably has 1 to 20 carbon atoms and a    carbon-containing radical R³⁰ including substituents preferably has    1 to 30 carbon atoms;-   R³¹ is hydrogen or (C₁-C₄)alkyl, preferably hydrogen, or-   R³⁰ and R³¹ together with the group of the formula —CO—N— are the    radical of the 3- to 8-membered saturated or unsaturated ring;-   R³² radicals are identical or different and are halogen, cyano,    nitro, amino, hydroxyl, carboxyl, formyl, CONH₂, SO₂NH₂ or a radical    of the formula -Z^(b)-R^(b);-   R³³ is hydrogen or (C₁-C₄)alkyl, preferably H;-   R³⁴ radicals are identical or different and are halogen, cyano,    nitro, amino, hydroxyl, carboxyl, CHO, CONH₂, SO₂NH₂ or a radical of    the formula -Z^(c)-R^(c);-   R^(a) is a hydrocarbon radical or heterocyclyl radical, where each    of the two last-mentioned radicals is unsubstituted or substituted    by one or more identical or different radicals selected from the    group consisting of halogen, cyano, nitro, amino, hydroxyl, mono-    and di[(C₁-C₄)alkyl]amino, or an alkyl radical in which a plurality    of, preferably 2 or 3, non-adjacent CH₂ groups are in each case    replaced by one oxygen atom;-   R^(b),R^(c) are identical or different hydrocarbon radicals or    heterocyclyl radicals, where each of the two last-mentioned radicals    is unsubstituted or substituted by one or more identical or    different radicals selected from the group consisting of halogen,    cyano, nitro, amino, hydroxyl, phosphoryl, halo(C₁-C₄)alkoxy, mono-    and di[(C₁-C₄)alkyl]amino, or an alkyl radical in which a plurality    of, preferably 2 or 3, non-adjacent CH₂ groups are in each case    replaced by one oxygen atom;-   Z^(a) is a divalent group of the formula —O—, —S—, —CO—, —CS—,    —CO—O—, —CO—S—, —O—CO—, —S—CO—, —SO—, —SO₂—, —NR*—, —CO—NR*—,    —NR*—CO—, —SO₂—NR*— or —NR*—SO₂—, where the bond indicated on the    right-hand side of the respective divalent group is the bond with    the radical R^(a) and where the R* radicals in the last-mentioned 5    radicals independently of one another are in each case H,    (C₁-C₄)alkyl or halo(C₁-C₄)alkyl;-   Z^(b),Z^(c) independently of one another are a direct bond or a    divalent group of the formula —O—, —S—, —CO—, —CS—, —CO—O—, —CO—S—,    —O—CO—, —S—CO—, —SO—, —SO₂—, —NR*—, —SO₂—NR*—, —NR*—SO₂, —CO—NR*— or    —NR*—CO—, where the bond indicated on the right-hand side of the    respective divalent group is the bond with the radical R^(b) or    R^(c) and where the R* radicals in the last-mentioned 5 radicals    independently of one another are in each case H, (C₁-C₄)alkyl or    halo(C₁-C₄)alkyl;-   n is an integer from 0 to 4, preferably 0, 1 or 2, in particular 0    or 1, and-   m is an integer from 0 to 5, preferably 0, 1, 2 or 3, in particular    0, 1 or 2;-   d) acylsulfamoylbenzamides of the general formula (V), if    appropriate also in salt form,    where-   X³ is CH or N;-   R³⁵ is hydrogen, heterocyclyl or a hydrocarbon radical, where the    two last-mentioned radicals are optionally substituted by one or    more, identical or different radicals selected from the group    consisting of halogen, cyano, nitro, amino, hydroxyl, carboxyl, CHO,    CONH₂, SO₂NH₂ and Z^(a)-R^(a);-   R³⁶ is hydrogen, hydroxyl, (C₁-C₆)alkyl, (C₂-C₆)alkenyl,    (C₂-C₆)alkynyl, (C₁-C₆)alkoxy, (C₂-C₆)alkenyloxy, where the five    last-mentioned radicals are optionally substituted by one or more,    identical or different radicals selected from the group consisting    of halogen, hydroxyl, (C₁-C₄)alkyl, (C₁-C₄)alkoxy and    (C₁-C₄)alkylthio, or-   R³⁵ and R³⁶ together with the nitrogen atom to which they are    attached are a 3- to 8-membered saturated or unsaturated ring;-   R³⁷ is halogen, cyano, nitro, amino, hydroxyl, carboxyl, CHO, CONH₂,    SO₂NH₂ or Z^(b)-R^(b);-   R³⁸ is hydrogen, (C₁-C₄)alkyl, (C₂-C₄)alkenyl or (C₂-C₄)alkynyl;-   R³⁹ is halogen, cyano, nitro, amino, hydroxyl, carboxyl, phosphoryl,    CHO, CONH₂, SO₂NH₂ or Z^(c)-R^(c);-   R^(a) is a (C₂-C₂₀)alkyl radical whose carbon chain is interrupted    once or more than once by oxygen atoms, or is heterocyclyl or a    hydrocarbon radical, where the two last-mentioned radicals are    optionally substituted by one or more, identical or different    radicals selected from the group consisting of halogen, cyano,    nitro, amino, hydroxyl, mono- and di[(C₁-C₄)alkyl]amino;-   R^(b), R^(c) are a (C₂-C₂₀)alkyl radical whose carbon chain is    interrupted once or more than once by oxygen atoms, or is    heterocyclyl or a hydrocarbon radical, where the two last-mentioned    radicals are optionally substituted by one or more, identical or    different radicals selected from the group consisting of halogen,    cyano, nitro, amino, hydroxyl, phosphoryl, (C₁-C₄)haloalkoxy, mono-    and di[(C₁-C₄)alkyl]amino;-   Z^(a) is a divalent unit selected from the group consisting of O, S,    CO, CS, C(O)O, C(O)S, SO, SO₂, NR^(d), C(O)NR^(d) or SO₂NR^(d);-   Z^(b), Z^(c) are identical or different and are a direct bond or a    divalent unit selected from the group consisting of O, S, CO, CS,    C(O)O, C(O)S, SO, SO₂, NR^(d), SO₂NR^(d) or C(O)NR^(d);-   R^(d) is hydrogen, (C₁-C₄)alkyl or (C₁-C₄)haloalkyl;-   n is an integer from 0 to 4, and-   m, in the event that X is CH, is an integer from 0 to 5 and in the    event that X is N, an integer from 0 to 4;-   e) compounds of the acylsulfamoylbenzamide type, for example of the    formula (VI) hereinbelow, some of which are known from WO 99/16744,    for example those in which-   R²¹=cyclopropyl and R²²=H(S3-1=4-cyclopropylaminocarbonyl-N-(2    methoxybenzoyl)benzenesulfonamide),-   R²¹=cyclopropyl and R²²=5-Cl(S3-2),-   R²¹=ethyl and R²²=H(S3-3),-   R²¹=isopropyl and R²²=5-Cl(S3-4) and-   R²¹=isopropyl and R²²=H(S3-5);-   f) Compounds of the N-acylsulfamoylphenylurea type of the formula    (VII), some of which are known from EP-A-365484,    where-   A is a radical selected from the group consisting of-   R^(α) and R^(β) independently of one another are hydrogen,    C₁-C₈-alkyl, C₃-C₈-cycloalkyl, C₃-C₆-alkenyl, C₃-C₆-alkynyl,-    or C₁-C₄-alkoxy which is substituted by Ry C₁-C₄-alkoxy or by-   R^(α) and R^(β) together are a C₄-C₆-alkylene bridge or a    C₄-C₆-alkylene bridge which is interrupted by oxygen, sulfur, SO,    SO₂, NH or —N(C₁-C₄-alkyl)-,-   R^(γ) is hydrogen or C₁-C₄-alkyl,-   R^(a) and R^(b) independently of one another are hydrogen, halogen,    cyano, nitro, trifluoromethyl, C₁-C₄-alkyl, C₁-C₄-alkoxy,    C₁-C₄-alkylthio, C₁-C₄-alkylsulfinyl, C₁-C₄-alkylsulfonyl,    —COOR^(j), —CONR^(k)R^(m), —COR^(n), SO₂NR^(k)R^(m), or    —OSO₂—C₁-C₄-alkyl, or R^(a) and R^(b) together are a C₃-C₄-alkylene    bridge which can be substituted by halogen or C₁-C₄-alkyl, or a    C₃-C₄-alkenylene bridge which can be substituted by halogen or    C₁-C₄-alkyl, or a C₄-alkadienylene bridge which can be substituted    by halogen or C₁-C₄-alkyl, and-   R^(g) and R^(h) independently of one another are hydrogen, halogen,    C₁-C₄-alkyl, trifluoromethyl, methoxy, methylthio or —COOR^(j),    where-   R^(c) is hydrogen, halogen, C₁-C₄-alkyl or methoxy,-   R^(d) is hydrogen, halogen, nitro, C₁-C₄-alkyl, C₁-C₄-alkoxy,    C₁-C₄-alkylthio, C₁-C₄-alkylsulfinyl, C₁-C₄-alkylsulfonyl, —COOR^(j)    or —CONR^(k)R^(m),-   R^(e) is hydrogen, halogen, C₁-C₄-alkyl, —COOR^(j), trifluoromethyl    or methoxy, or R^(d) and R^(e) together are a C₃-C₄-alkylene bridge,-   R^(f) is hydrogen, halogen or C₁-C₄-alkyl,-   R^(X) and R^(Y) independently of one another are hydrogen, halogen,    C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-alkylthio, —COOR^(j),    trifluoromethyl, nitro or cyano,-   R^(j), R^(k) and R^(m) independently of one another are hydrogen or    C₁-C₄-alkyl,-   R^(k) and R^(m) together are a C₄-C₆-alkylene bridge or a    C₄-C₆-alkylene bridge which is interrupted by oxygen, NH or    —N(C₁-C₄-alkyl)-, and-   R^(n) is C₁-C₄-alkyl, phenyl or phenyl which is substituted by    halogen, C₁-C₄-alkyl, methoxy, nitro or trifluoromethyl,    preferably-   1-[4-(N-2-methoxybenzoylsulfamoyl)phenyl]-3-methylurea,-   1-[4-(N-2-methoxybenzoylsulfamoyl)phenyl]-3,3-dimethylurea,-   1-[4-(N-4,5-dimethylbenzoylsulfamoyl)phenyl]-3-methylurea,-   1-[4-(N-naphthoylsulfamoyl)phenyl]-3,3-dimethylurea,-   g) compounds of the acylsulfamoylbenzamide type of the formula    (VIII), disclosed in EP-A-1019368, if appropriate also in salt form,    where-   R¹ is methyl, methoxy or trifluoromethoxy;-   R² is hydrogen, chlorine or methyl;-   R³ is hydrogen, ethyl or propargyl;-   R⁴ is ethyl, cyclopropyl, iso-propyl or propargyl, or-   R³ and R⁴ together form the group (CH₂)₄,    including the stereoisomers and including the salts which are    conventionally used in agriculture.

The compounds of the formula (I) are disclosed for example in EP-A-0 333131 (ZA-89/1960), EP-A-0 269 806 (U.S. Pat. No. 4,891,057), EP-A-0 346620 (AU-A-89/34951), EP-A-0 174 562, EP-A-0 346 620 (WO-A-91108 202),WO-A-91107 874 or WO-A 95/07 897 (ZA 94/7120) and the literature citedtherein or can be prepared by, or in analogy with, the processesdescribed therein.

The compounds of the formula (II) are disclosed for example in EP-A-0086 750, EP-A-0 94349 (U.S. Pat. No. 4,902,340), EP-A-0 191736 (U.S.Pat. No. 4,881,966) and EP-A-0 492 366 and the literature cited thereinor can be prepared by, or in analogy with, the processes describedtherein. Some compounds are furthermore described in EP-A-0 582 198 andWO 2002/34048.

The compounds of the formula (III) are known from a large number ofpatent applications, for example U.S. Pat. No. 4,021,224 and U.S. Pat.No. 4,021,229.

Compounds of group (b) are furthermore known from CN-A-87/102 789,EP-A-365484 and from “The Pesticide Manual”, The British Crop ProtectionCouncil and the Royal Society of Chemistry, 11th edition, Farnham 1997.

The compounds of group (c) are described in WO-A-97/45016, those ofgroup (d) in WO-A-99/16744, those of group B (e) in EP-A-365484 andthose of group (g) in EP-A-1019368.

The publications cited contain extensive information on preparationprocesses and starting materials and detail preferred compounds. Thesepublications are expressly referred to herewith; they are incorporatedinto the present description by reference.

Preferred compounds of the formula (I) and/or (II) which are known assafeners are those in which the symbols and indices have the followingmeanings:

-   R²⁴ is hydrogen, (C₁-C₁₈)alkyl, (C₃-C₁₂)cycloalkyl, (C₂-C₈)alkenyl    and (C₂-C₁₈)alkynyl, where the carbon-containing groups can be    substituted by one or more, preferably up to three, radicals R⁵⁰;-   R⁵⁰ is identical or different and is halogen, hydroxyl,    (C₁-C₈)alkoxy, (C₁-C₈)alkylthio, (C₂-C₈)alkenylthio,    (C₂-C₈)alkynylthio, (C₂-C₈)alkenyloxy, (C₂-C₈)alkynyloxy,    (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkoxy, cyano, mono- and    di((C₁-C₄)alkyl)amino, carboxyl, (C₁-C₈)alkoxycarbonyl,    (C₂-C₈)alkenyloxycarbonyl, (C₁-C₈)alkylthiocarbonyl,    (C₂-C₈)alkynyloxycarbonyl, (C₁-C₈)alkylcarbonyl,    (C₂-C₈)alkenylcarbonyl, (C₂-C₈)alkynylcarbonyl,    1-(hydroxyimino)(C₁-C₆)alkyl, 1-[(C₁-C₄)alkylimino]-(C₁-C₄)alkyl,    1-[(C₁-C₄)alkoxyimino](C₁-C₆)alkyl, (C₁-C₈)alkylcarbonylamino,    (C₂-C₈)alkenylcarbonylamino, (C₂-C₈)alkynylcarbonylamino,    aminocarbonyl, (C₁-C₈)alkylaminocarbonyl,    di(C₁-C₆)alkylaminocarbonyl, (C₂-C₆)alkenylaminocarbonyl,    (C₂-C₆)alkynylaminocarbonyl, (C₁-C₈)alkoxycarbonylamino,    (C₁-C₈)alkylaminocarbonylamino, (C₁-C₆)alkylcarbonyloxy which is    unsubstituted or substituted by R⁵, or are    (C₂-C₆)alkenylcarbonyloxy, (C₂-C₆)alkynylcarbonyloxy,    (C₁-C₈)alkylsulfonyl, phenyl, phenyl(C₁-C₆)alkoxy,    phenyl(C₁-C₆)alkoxycarbonyl, phenoxy, phenoxy(C₁-C₆)alkoxy,    phenoxy(C₁-C₆)alkoxycarbonyl, phenylcarbonyloxy,    phenylcarbonylamino, phenyl(C₁-C₆)alkylcarbonylamino, where the 9    last-mentioned radicals are unsubstituted or mono- or    polysubstituted, preferably up to trisubstituted, in the phenol ring    by radicals R⁵²; SiR′₃, —O—SiR′₃, R′₃Si(C₁-C₈)alkoxy, —CO—O—NR′₂,    —O—N═CR′₂, —N═CR′₂, —O—NR′₂, —NR′₂, CH(OR′)₂, —O—(CH₂)_(m)—CH(OR′)₂,    —CR′″(OR′)₂, —O—(CH₂)_(m)CR′″(OR″)₂ or by    R″O—CHR′″CHCOR″—(C₁-C₆)alkoxy,-   R⁵¹ is identical or different and is halogen, nitro, (C₁-C₄)alkoxy    and phenyl which is unsubstituted or substituted by one or more,    preferably up to three, radicals R⁵²;-   R⁵² is identical or different and is halogen, (C₁-C₄)alkyl,    (C₁-C₄)alkoxy, (C₁-C₄)haloalkyl, (C₁-C₄)haloalkoxy or nitro;-   R′ is identical or different and is hydrogen, (C₁-C₄)alkyl,    unsubstituted phenyl or phenyl which is substituted by one or more,    preferably by up to three, radicals R⁵², or two radicals R′ together    form a (C₂-C₆)alkanediyl chain;-   R″ is identical or different and is (C₁-C₄)alkyl, or two radicals R″    together form a (C₂-C₆)alkanediyl chain;-   R′″ is hydrogen or (C₁-C₄)alkyl;-   m is 0, 1, 2, 3, 4, 5 or 6.

Especially preferred compounds of the formula (I) and (II) which areknown as safeners are those in which the symbols and indices have thefollowing meanings:

-   R²⁴ is hydrogen, (C₁-C₈)alkyl or (C₃-C₇)cycloalkyl, where the above    carbon-containing radicals are unsubstituted or mono- or    polysubstituted by halogen or mono- or disubstituted, preferably    monosubstituted, by radicals R⁵⁰,-   R⁵⁰ is identical or different and is hydroxyl, (C₁-C₄)alkoxy,    carboxyl, (C₁-C₄)alkoxycarbonyl, (C₂-C₆)alkenyloxycarbonyl,    (C₂-C₆)alkynyloxycarbonyl, 1-(hydroxyimino)(C₁-C₄)alkyl,    1-[(C₁-C₄)alkylimino](C₁-C₄)alkyl and    1-[(C₁-C₄)alkoxyimino](C₁-C₄)alkyl; -SiR′₃, —O—N═CR′₂, —N═CR′₂,    —NR′₂, and —O—NR′₂, where R′ is identical or different and is    hydrogen, (C₁-C₄)alkyl or in groups of two is a (C₄-C₅)alkanediyl    chain,-   R²⁷, R²⁸, R²⁹ are identical or different and are hydrogen,    (C₁-C₈)alkyl, (C₁-C₆)haloalkyl, (C₃-C₇)cycloalkyl or phenyl which is    unsubstituted or substituted by one or more radicals selected from    the group consisting of halogen, cyano, nitro, amino, mono- and    di[(C₁-C₄)alkyl]amino, (C₁-C₄)alkyl, (C₁-C₄)haloalkyl,    (C₁-C₄)alkoxy, (C₁-C₄)haloalkoxy, (C₁-C₄)alkylthio and    (C₁-C₄)alkylsulfonyl;-   R^(x) is hydrogen or COOR²⁶, where R²⁶ is hydrogen, (C₁-C₈)alkyl,    (C₁-C₈)haloalkyl, (C₁-C₄-alkoxy)(C₁-C₄)alkyl, (C₁-C₆)hydroxyalkyl,    (C₃-C₇)cycloalkyl or tri(C₁-C₄)alkylsilyl,-   R¹⁷, R¹⁹ are identical or different and are halogen, methyl, ethyl,    methoxy, ethoxy, (C₁ or C₂)haloalkyl, preferably hydrogen, halogen    or (C₁ or C₂)haloalkyl.

Very especially preferred compounds which are known as safeners arethose in which the symbols and indices in formula (I) have the followingmeanings:

-   R¹⁷ is halogen, nitro or (C₁-C₄)haloalkyl;-   n′ is 0, 1, 2 or 3;-   R¹⁸ is a radical of the formula OR²⁴,-   R²⁴ is hydrogen, (C₁-C₈)alkyl or (C₃-C₇)cycloalkyl, where the above    carbon-containing radicals are unsubstituted or mono- or    polysubstituted, preferably up to trisubstituted, by identical or    different halogen radicals or up to disubstituted, preferably    monosubstituted, by identical or different radicals selected from    the group consisting of hydroxyl, (C₁-C₄)alkoxy,    (C₁-C₄)alkoxycarbonyl, (C₂-C₆)alkenyloxycarbonyl,    (C₂-C₆)alkynyloxycarbonyl, 1-(hydroxyimino)(C₁-C₄)alkyl,    1-[(C₁-C₄)alkylimino](C₁-C₄)alkyl,    1-[(C₁-C₄)alkoxyimino](C₁-C₄)alkyl and radicals of the formulae    —SiR′₃, —O—N═R′₂, —N═CR′₂, —NR′₂ and —O—NR′₂, where the radicals R′    in the above formulae are identical or different and are hydrogen,    (C₁-C₄)alkyl or in groups of two are (C₄ or C₅)alkanediyl;-   R²⁷, R²⁸, R²⁹ are identical or different and are hydrogen,    (C₁-C₈)alkyl, (C₁-C₆)haloalkyl, (C₃-C₇)cycloalkyl or phenyl which is    unsubstituted or substituted by one or more of the radicals selected    from the group consisting of halogen, (C₁-C₄)alkyl, (C₁-C₄)alkoxy,    nitro, (C₁-C₄)haloalkyl and (C₁-C₄)haloalkoxy, and-   R^(x) is hydrogen or COOR²⁶, where R²⁶ is hydrogen, (C₁-C₈)alkyl,    (C₁-C₈)haloalkyl, (C₁-C₄)alkoxy(C₁-C₄)alkyl, (C₁-C₆)hydroxyalkyl,    (C₃-C₇)cycloalkyl or tri(C₁-C₄)alkylsilyl.

Also very especially preferred compounds of the formula (II) which areknown as safeners are those in which the symbols and indices have thefollowing meanings:

-   R¹⁹ is halogen or (C₁-C₄)haloalkyl;-   n′ is 0, 1, 2 or 3, where (R¹⁹)_(n) is preferably 5-Cl;-   R²⁰ is a radical of the formula OR²⁴;-   T is CH₂ or CH(COO—(C₁-C₃-alkyl)) and-   R²⁴ is hydrogen, (C₁-C₈)alkyl, (C₁-C₈)haloalkyl or    (C₁-C₄)alkoxy(C₁-C₄)alkyl, preferably hydrogen or (C₁-C₈)alkyl.

In this context, particularly preferred compounds of the formula (I)which are known as safeners are those in which the symbols and indiceshave the following meanings:

-   W is (W1);-   R¹⁷ is halogen or (C₁-C₂)haloalkyl;-   n′ is 0, 1, 2 or 3, where (R¹⁷)_(n) is preferably 2,4-Cl₂;-   R¹⁸ is a radical of the formula OR²⁴;-   R²⁴ is hydrogen, (C₁-C₈)alkyl, (C₁-C₄)haloalkyl,    (C₁-C₄)hydroxyalkyl, (C₃-C₇)cyclo-alkyl, (C₁-C₄)alkoxy(C₁-C₄)alkyl    or tri(C₁-C₂)alkylsilyl, preferably (C₁-C₄)alkyl;-   R²⁷ is hydrogen, (C₁-C₈)alkyl, (C₁-C₄)haloalkyl or    (C₃-C₇)cycloalkyl, preferably hydrogen or (C₁-C₄)alkyl, and-   R^(x) is COOR²⁶, where R²⁶ is hydrogen, (C₁-C₈)alkyl,    (C₁-C₄)haloalkyl, (C₁-C₄)hydroxyalkyl, (C₃-C₇)cycloalkyl,    (C₁-C₄)alkoxy(C₁-C₄)alkyl or tri(C₁-C₂)alkylsilyl, preferably    hydrogen or (C₁-C₄)alkyl.

Other particularly preferred compounds of the formula (I) which areknown as safeners are those in which the symbols and indices have thefollowing meanings:

-   W is (W2);-   R¹⁷ is halogen or (C₁-C₂)haloalkyl;-   n′ is 0, 1, 2 or 3, where (R¹⁷)_(n)— is preferably 2,4-Cl₂;-   R¹⁸ is a radical of the formula OR²⁴;-   R²⁴ is hydrogen, (C₁-C₈)alkyl, (C₁-C₄)haloalkyl,    (C₁-C₄)hydroxyalkyl, (C₃-C₇)cyclo-alkyl, (C₁-C₄)alkoxy(C₁-C₄)alkyl    or tri(C₁-C₂)alkylsilyl, preferably (C₁-C₄)alkyl, and-   R²⁷ is hydrogen, (C₁-C₈)alkyl, (C₁-C₄)haloalkyl, (C₃-C₇)cycloalkyl    or unsubstituted or substituted phenyl, preferably hydrogen,    (C₁-C₄)alkyl or phenyl which is unsubstituted or substituted by one    or more radicals selected from the group consisting of halogen,    (C₁-C₄)alkyl, (C₁-C₄)haloalkyl, nitro, cyano or (C₁-C₄)alkoxy.

Other particularly preferred compounds of the formula (I) which areknown as safeners are those in which the symbols and indices have thefollowing meanings:

-   W is (W3);-   R¹⁷ is halogen or (C₁-C₂)haloalkyl;-   n′ is 0, 1, 2 or 3, where (R¹⁷)_(n)— is preferably 2,4-Cl₂;-   R¹⁸ is a radical of the formula OR²⁴;-   R²⁴ is hydrogen, (C₁-C₈)alkyl, (C₁-C₄)haloalkyl,    (C₁-C₄)hydroxyalkyl, (C₃-C₇)cycloalkyl, (C₁-C₄)alkoxy(C₁-C₄)alkyl or    tri(C₁-C₂)alkylsilyl, preferably (C₁-C₄)alkyl, and-   R²⁸ is (C₁-C₈)alkyl or (C₁-C₄)haloalkyl, preferably C₁-haloalkyl.

Other especially preferred compounds of the formula (I) which are knownas safeners are those in which the symbols and indices have thefollowing meanings:

-   W is (W4);-   R¹⁷ is halogen, nitro, (C₁-C₄)alkyl, (C₁-C₂)haloalkyl, preferably    CF₃, or (C₁-C₄)alkoxy;-   n′ is 0, 1, 2 or 3;-   m′ is 0 or 1;-   R¹⁸ is a radical of the formula OR²⁴;-   R²⁴ is hydrogen, (C₁-C₄)alkyl, carboxy(C₁-C₄)alkyl,    (C₁-C₄)alkoxycarbonyl(C₁-C₄)alkyl, preferably (C₁-C₄)alkoxy-CO—CH₂—,    (C₁-C₄)alkoxy-CO—C(CH₃)H—, HO—CO—CH₂— or HO—CO—C(CH₃)H—, and-   R²⁹ is hydrogen, (C₁-C₄)alkyl, (C₁-C₄)haloalkyl, (C₃-C₇)cycloalkyl    or phenyl which is unsubstituted or substituted by one or more    radicals selected from the group consisting of halogen,    (C₁-C₄)alkyl, (C₁-C₄)haloalkyl, nitro, cyano and (C₁-C₄)alkoxy.

The following groups of compounds which are known as safeners areparticularly suitable as active substances for increasing the toleranceof plants to abiotic stress factors:

-   a) compounds of the dichlorophenylpyrazoline-3-carboxylic acid type    (i.e. of the formula (I) in which W=(W1) and (R¹⁷)_(n′)=2,4-Cl₂),    preferably compounds such as ethyl    1-(2,4-dichlorophenyl)-5-(ethoxycarbonyl)-5-methyl-2-pyrazoline-3-carboxylate    (I-1, mefenpyr-diethyl), mefenpyr-dimethyl and mefenpyr (I-0), and    related compounds as they are described in WO-A 91/07874;-   b) dichlorophenylpyrazolecarboxylic acid derivatives (i.e. of the    formula (I) where W=(W2) and (R¹⁷)_(n′)=2,4-Cl₂), preferably    compounds such as ethyl    1-(2,4-dichlorophenyl)-5-methylpyrazole-3-carboxylate (I-2), ethyl    1-(2,4-dichlorophenyl)-5-isopropylpyrazole-3-carboxylate (I-3),    ethyl    1-(2,4-dichlorophenyl)-5-(1,1-dimethylethyl)pyrazole-3-carboxylate    (I-4), ethyl 1-(2,4-dichlorophenyl)-5-phenylpyrazole-3-carboxylate    (I-5) and related compounds as they are described in EP-A-0 333 131    and EP-A-0 269 806;-   c) compounds of the triazolecarboxylic acid type (i.e. of the    formula (I) where W=(W3) and (R¹⁷)_(n′)=2,4-Cl₂), preferably    compounds such as fenchlorazole-ethyl, i.e. ethyl    1-(2,4-dichlorophenyl)-5-trichloromethyl-(1H)-1,2,4-triazole-3-carboxylate    (I-6), and related compounds (see EP-A-0 174 562 and EP-A-0 346    620);-   d) compounds of the 5-benzyl- or 5-phenyl-2-isoxazoline-3-carboxylic    acid type or of the 5,5-diphenyl-2-isoxazoline-3-carboxylic acid    type, such as isoxadifen (I-12), (where W=(W4)), preferably    compounds such as ethyl    5-(2,4-dichlorobenzyl)-2-isoxazoline-3-carboxylate (I-7) or ethyl    5-phenyl-2-isoxazoline-3-carboxylate (I-8), and related compounds as    they are described in WO-A-91/08202, or of the    5,5-diphenyl-2-isoxazolinecarboxylate type (I-9, isoxadifen-ethyl)    or of the n-propyl 5,5-diphenyl-2-isoxazolinecarboxylate type (I-10)    or of the ethyl    5-(4-fluorophenyl)-5-phenyl-2-isoxazoline-3-carboxylate type (I-11),    as they are described in WO-A-95/07897.-   e) Compounds of the 8-quinolinoxyacetic acid type, for example those    of the formula (II), where (R¹⁹)_(n′)=5-Cl, R²⁰=OR²⁴ and T=CH₂,    preferably the compounds-   1-methylhexyl (5-chloro-8-quinolinoxy)acetate (II-1,    cloquintocet-mexyl),-   1,3-dimethylbut-1-yl (5-chloro-8-quinolinoxy)acetate (II-2),-   4-allyloxybutyl (5-chloro-8-quinolinoxy)acetate (II-3),-   1-allyloxyprop-2-yl (5-chloro-8-quinolinoxy)acetate (II-4),-   ethyl(5-chloro-8-quinolinoxy)acetate (II-5),-   methyl(5-chloro-8-quinolinoxy)acetate (II-6),-   allyl(5-chloro-8-quinolinoxy)acetate (II-7),-   2-(2-propylideneiminooxy)-1-ethyl (5-chloro-8-quinolinoxy)acetate    (II-8),-   2-oxoprop-1-yl (5-chloro-8-quinolinoxy)acetate (II-9),-   (5-chloro-8-quinolinoxy)acetic acid (II-10) and its salts as they    are described for example in WO-A-2002/34048,-   and related compounds as they are described in EP-A-0 860 750,    EP-A-0 094 349 and EP-A-0 191 736 or EP-A-0 492 366.-   f) Compounds of the (5-chloro-8-quinolinoxy)malonic acid type, i.e.    of the formula (II) where (R¹⁹)_(n′)=5-Cl, R²⁰=OR²⁴,    T=—CH(COO-alkyl)-, preferably the compounds diethyl    (5-chloro-8-quinolinoxy)malonate (II-11),    diallyl(5-chloro-8-quinolinoxy)malonate, methyl    ethyl(5-chloro-8-quinolinoxy)malonate and related compounds as they    are described in EP-A-0 582 198.-   9) Compounds of the dichloroacetamide type, i.e. of the formula    (III), preferably:-   N,N-diallyl-2,2-dichloroacetamide (dichlormid (III-1), from U.S.    Pat. No. 4,137,070),-   4-dichloroacetyl-3,4-dihydro-3-methyl-2H-1,4-benzoxazine (IV-2,    Benoxacor, from EP 0 149 974),-   N1,N2-diallyl-N-2-dichloroacetylglycinamide (DKA-24 (111-3), from HU    2143821),-   4-dichloroacetyl-1-oxa-4-aza-spiro[4,5]decane (AD-67),-   2,2-dichloro-N-(1,3-dioxolan-2-ylmethyl)-N-(2-propenyl)acetamide    (PPG-1292),-   3-dichloroacetyl-2,2,5-trimethyloxazolidine (R-29148, III-4),-   3-dichloroacetyl-2,2-dimethyl-5-phenyloxazolidine,-   3-dichloroacetyl-2,2-dimethyl-5-(2-thienyl)oxazolidine,-   3-dichloroacetyl-5-(2-furanyl)-2,2-dimethyloxazolidine (furilazole    (III-5), MON 13900),-   1-dichloroacetylhexahydro-3,3,8a-trimethylpyrrolo[1,2-a]pyrimidin-6(2H)-one    (dicyclonon, BAS 145138),-   h) compounds from group (b), preferably-   1,8-naphthalic anhydride (b-1),-   methyldiphenyl methoxyacetate (b-2),-   cyanomethoxyimino(phenyl)acetonitrile (cyometrinil) (b-3),-   1-(2-chlorobenzyl)-3-(1-methyl-1-phenylethyl)urea (cumyluron) (b-4),-   O,O-diethyl S-2-ethylthioethyl phosphorodithioate (disulfoton)    (b-5),-   4-chlorophenyl methylcarbamate (mephenate) (b-6),-   O,O-diethyl O-phenyl phosphorothioate (dietholate) (b-7),-   4-carboxy-3,4-dihydro-2H-1-benzopyran-4-acetic acid (CL-304415,    CASReg. No: 31541-57-8) (b-8),-   1,3-dioxolan-2-ylmethoxyimino(phenyl)acetonitrile (oxabetrinil)    (b-9),-   4′-chloro-2,2,2-trifluoroacetophenone O-1,3-dioxolan-2-ylmethyloxime    (fluxofenim) (b-10),-   4,6-dichloro-2-phenylpyrimidine (fenclorim) (b-11),-   benzyl 2-chloro-4-trifluoromethyl-1,3-thiazole-5-carboxylate    (flurazole) (b-12),-   2-dichloromethyl-2-methyl-1,3-dioxolane (MG-191) (b-13),-   N-(4-methylphenyl)-N′-(1-methyl-1-phenylethyl)urea (dymron) (b-14),-   (2,4-dichlorophenoxy)acetic acid (2,4-D),-   (4-chlorophenoxy)acetic acid,-   (R,S)-2-(4-chloro-o-tolyloxy)propionic acid (mecoprop),-   4-(2,4-dichlorophenoxy)butyric acid (2,4-DB),-   (4-chloro-o-tolyloxy)acetic acid (MCPA),-   4-(4-chloro-o-tolyloxy)butyric acid,-   4-(4-chlorophenoxy)butyric acid,-   3,6-dichloro-2-methoxybenzoic acid (dicamba),-   1-(ethoxycarbonyl)ethyl 3,6-dichloro-2-methoxybenzoate    (lactidichlor) and their salts and esters, preferably (C₁-C₈).

Furthermore preferred compounds of the formula (IV) or their salts whichare known as safeners are those in which

-   R³⁰ is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, furanyl or    thienyl, where each of the 4 last-mentioned radicals is    unsubstituted or substituted by one or more substituents selected    from the group consisting of halogen, (C₁-C₄)alkoxy, halo    (C₁-C₆)alkoxy and (C₁-C₄)alkylthio and in the case of cyclic    radicals also by (C₁-C₄)alkyl and (C₁-C₄)haloalkyl,-   R³¹ is hydrogen,-   R³² is halogen, halo(C₁-C₄)alkyl, halo(C₁-C₄)alkoxy, (C₁-C₄)alkyl,    (C₁-C₄)alkoxy, (C₁-C₄)alkylsulfonyl, (C₁-C₄)alkoxycarbonyl or    (C₁-C₄)alkylcarbonyl, preferably halogen, (C₁-C₄) haloalkyl, such as    trifluoromethyl, (C₁-C₄)alkoxy, halo(C₁-C₄)alkoxy,    (C₁-C₄)alkoxycarbonyl or (C₁-C₄)alkylsulfonyl,-   R³³ is hydrogen,-   R³⁴ is halogen, (C₁-C₄)alkyl, halo(C₁-C₄)alkyl, halo(C₁-C₄)alkoxy,    (C₃-C₆)cycloalkyl, phenyl, (C₁-C₄)alkoxy, cyano, (C₁-C₄)alkylthio,    (C₁-C₄)alkylsulfinyl, (C₁-C₄)alkylsulfonyl, (C₁-C₄)alkoxycarbonyl or    (C₁-C₄)alkylcarbonyl,    -   preferably halogen, (C₁-C₄)alkyl, (C₁-C₄)haloalkyl such as        trifluoromethyl, halo(C₁-C₄)alkoxy, (C₁-C₄)alkoxy or        (C₁-C₄)alkylthio,-   n is 0, 1 or 2 and-   m is 1 or 2.

Especially preferred compounds of the formula (IV) which are known assafeners are those in which

-   R³⁰=H₃C—O—CH₂—, R³¹=R³³=H, R³⁴=2-OMe (IV-1),-   R³⁰=H₃C—O—CH₂—, R³¹=R³³=H, R³⁴=2-OMe-5-Cl (IV-2),-   R³⁰=cyclopropyl, R³¹=R³³=H, R³⁴=2-OMe (IV-3),-   R³⁰=cyclopropyl, R³¹=R³³=H, R³⁴=2-OMe-5-Cl (IV-4),-   R³⁰=cyclopropyl, R³¹=R³³=H, R³⁴=2-Me (IV-5),-   R³⁰=tert-butyl, R³¹=R³³=H, R³⁴=2-OMe (IV-6).

Furthermore preferred compounds of the formula (V) which are known assafeners are those in which

-   X³ is CH;-   R³⁵ is hydrogen, (C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, (C₂-C₆)alkenyl,    (C₅-C₆)cycloalkenyl, phenyl or 3- to 6-membered heterocyclyl having    up to three heteroatoms selected from the group consisting of    nitrogen, oxygen and sulfur, where the six last-mentioned radicals    are optionally substituted by one or more identical or different    substituents selected from the group consisting of halogen,    (C₁-C₆)alkoxy, (C₁-C₆)haloalkoxy, (C₁-C₂)alkylsulfinyl,    (C₁-C₂)alkyl-sulfonyl, (C₃-C₆)cycloalkyl, (C₁-C₄)alkoxycarbonyl,    (C₁-C₄)alkylcarbonyl and phenyl and in the case of cyclic radicals    also by (C₁-C₄)alkyl and (C₁-C₄)haloalkyl;-   R³⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl, (C₂-C₆)alkynyl, where    the three last-mentioned radicals are optionally substituted by one    or more identical or different substituents selected from the group    consisting of halogen, hydroxyl, (C₁-C₄)alkyl, (C₁-C₄)alkoxy and    (C₁-C₄)alkylthio;-   R³⁷ is halogen, (C₁-C₄)haloalkyl, (C₁-C₄)haloalkoxy, nitro,    (C₁-C₄)alkyl, (C₁-C₄)alkoxy, (C₁-C₄)alkylsulfonyl,    (C₁-C₄)alkoxycarbonyl or (C₁-C₄)alkylcarbonyl;-   R³⁸ is hydrogen;-   R³⁹ is halogen, nitro, (C₁-C₄)alkyl, (C₁-C₄)haloalkyl,    (C₁-C₄)haloalkoxy, (C₃-C₆)cycloalkyl, phenyl, (C₁-C₄)alkoxy, cyano,    (C₁-C₄)alkylthio, (C₁-C₄)alkylsulfinyl, (C₁-C₄)alkylsulfonyl,    (C₁-C₄)alkoxycarbonyl or (C₁-C₄)alkylcarbonyl;-   n is 0, 1 or 2 and-   m is 1 or 2.

Preferred compounds of the formula (VI) which are known as safeners are(S3-1), (S3-2), (S3-3), (S3-4) and (S3-5).

Other preferred compounds of the formula (VII) are

-   1-[4-(N-2-methoxybenzoylsulfamoyl)phenyl]-3-methylurea (VII-1),-   1-[4-(N-2-methoxybenzoylsulfamoyl)phenyl]-3,3-dimethylurea (VII-2),-   1-[4-(N-4,5-dimethylbenzoylsulfamoyl)phenyl]-3-methylurea (VII-3)    and-   1-[4-(N-naphthoylsulfamoyl)phenyl]-3,3-dimethylurea (VII-4).

Likewise preferred compounds are those of the formulae VIII-1 to VIII-4

of which, in turn, the compound VIII-3(4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide) isvery especially preferred for use as agent for increasing the tolerancein plants to abiotic stress factors.

Especially preferred compounds for use as agents for increasing thetolerance in plants to abiotic stress factors are those which areselected from the group of compounds known as safeners which consists ofthe compounds of the formulae I-1 (mefenpyr-diethyl), I-9(isoxadifen-ethyl), II-1 (chloquintocet-mexyl), b-11 (fenclorim), b-14(dymron), and VIII-3(4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide, withthe compounds I-1 and VIII-3 being very especially preferred).

The compounds identified/mentioned above, which, under certaincircumstances, may already be known as safeners, can already be employedin genetically modified plants.

The genetically modified plants (also referred to as transgenic plants)are, as a rule, distinguished by particular advantageous properties, forexample by resistances to certain pesticides, especially certainherbicides, resistances to plant diseases or pathogen agents of plantdiseases, such as certain insects or microorganisms such as fungi,bacteria or viruses. Other particular properties concern for example theharvested material with regard to quantity, quality, storage ability,composition and specific constituents. Thus, there are known transgenicplants with an increased starch content or a modified starch quality, orthose where the harvested material has a different fatty acidcomposition.

Preferred is the use of the identified/mentioned compounds, which areknown as safeners, or the salts of these compounds in economicallyimportant transgenic crops of useful plants and ornamentals, for examplecereals such as wheat, barley, rye, oats, sorghum and millet, rice andmaize or else crops of sugar beet, cotton, soya, oilseed rape, potato,tomato, pea and other vegetables, especially preferably in crops ofmaize, wheat, barley, rye, oats, rice, oilseed rape, sugar beet andsoya, very especially preferably in crops of maize, wheat, rice, oilseedrape, sugar beet and soya.

In addition, transgenic plants can also be treated with substancesidentified with the aid of DNA microarrays, such as the molecules whichare already known as safeners, whose tolerance to abiotic stress factorshas already been increased as the result of recombinant methods, so thata synergistic effect of the endogenously encoded tolerance and theextraneously applied tolerance-increasing effect is observed.

Conventional ways of generating novel plants which have modifiedproperties in comparison with existing plants are, for example,traditional breeding methods and the generation of mutants. As analternative, novel plants with modified properties can be generated withthe aid of recombinant methods (see, for example, EP-A-0221044,EP-A-0131624). The following have been described in a plurality ofcases: for example

-   -   recombinant modifications of crop plants in order to modify the        starch synthetized in the plants (for example WO 92/11376, WO        92/14827, WO 91/19806),    -   transgenic crop plants which are resistant to certain herbicices        of the glufosinate type (cf., for example, EP-A-0242236,        EP-A-242246) or of the glyphosate type (WO 92/00377) or of the        sulfonylurea type (EP-A-0257993, U.S. Pat. No. 5,013,659),    -   transgenic crop plants, for example cotton, with the ability to        produce Bacillus thuringiensis toxins (Bt toxins), which make        the plants resistant to certain pests (EP-A-0142924,        EP-A-0193259),    -   transgenic crop plants with a modified fatty acid composition        (WO 91/13972).

A large number of molecular-biological techniques with the aid of whichnovel transgenic plants with modified properties can be generated areknown in principle; see, for example, Sambrook et al., 1989, MolecularCloning, A Laboratory Manual, 2nd Edition, Cold Spring Harbor LaboratoryPress, Cold Spring Harbor, N.Y.; or Winnacker “Gene und Klone”, VCHWeinheim 2nd Edition, 1996 or Christou, “Trends in Plant Science” 1(1996) 423-431).

To carry out such recombinant manipulations, nucleic acid molecules canbe introduced into plasmids which permit a mutagenesis or a sequencemodification by means of the recombination of DNA sequences. With theaid of the abovementioned standard methods, it is possible for exampleto carry out base substitutions, to remove part-sequences or to addnatural or synthetic sequences. To link the DNA fragments with oneanother, adapters or linkers can be added to the fragments.

The generation of plant cells with a reduced activity of a gene productcan be accomplished for example by expressing at least one suitableantisense RNA, a sense RNA for achieving a cosuppression effect or theexpression of at least one suitably constructed ribosyme whichspecifically cleaves transcripts of the abovementioned gene product.

For this purpose, it is possible to use firstly DNA molecules whichcomprise all of the coding sequence of a gene product including anyflanking sequences which are present, or else DNA molecules which onlycomprise parts of the coding sequence, it being necessary for theseparts to be long enough in order to bring about an antisense effect inthe cells. Also possible is the use of DNA sequences which have a highdegree of homology with the coding sequences of a gene product, butwhich are not completely identical.

When expressing nucleic acid molecules in plants, the proteinsynthetized can be located in any compartment of the plant cell. Inorder to achieve the localization in a particular compartment, however,it is possible for example to link the coding region with DNA sequenceswhich ensure the localization in a particular compartment. Suchsequences are known to a person skilled in the art (see, for example,Braun et al., EMBO J. 11 (1992), 3219-3227; Wolter et al., Proc. Natl.Acad. Sci. USA 85 (1988), 846-850; Sonnewald et al., Plant J. 1 (1991),95-106).

The transgenic plant cells can be regenerated to give intact plants,using known techniques. The transgenic plants can, in principle, takethe form of plants of any plant species, i.e. both monocots and dicots.

Thus, transgenic plants are obtainable which have modified properties asthe result of the overexpression, suppression or inhibition ofhomologous (=natural) genes or gene sequences or the expression ofheterologous (=foreign) genes or gene sequences.

Preferably, the molecules which have been identified with the aid of theDNA microarrays or which are known as safeners can be employed intransgenic crops which are resistant to herbicides from the group of thesulfonylureas, glufosinate-ammonium or glyphosate-isopropylammonium andanalogous active substances and/or which have, as the result ofrecombinant modification, an endogenous tolerance to abiotic stressfactors.

When applying the active substances according to the invention intransgenic crops, effects which are specific for the application in thetransgenic crop in question are frequently observed in addition to theeffects against harmful plants which can be observed in other crops; forexample a modified or specifically widened weed spectrum which can becontrolled, modification application rates which can be used for theapplication, preferably good combining ability with the herbicides towhich the transgenic crop is resistant, and influencing the growth andyield of the transgenic crop plants.

The invention therefore also relates to the use of the compoundsidentified with DNA microarrays, or of compounds which are already knownas safeners, for increasing the tolerance to abiotic stress factors intransgenic crop plants, preferably with the purpose of increasing theyield.

The present invention relates to a method of finding a compound whichincreases the tolerance to abiotic stress factors in plants, theincrease in the transcription or expression of individual or moreplant-endogenous genes, such as, for example, genes coding for proteinsfrom the group of the cytochrome oxidases, such as cytochrome oxidaseP450, glycosyltransferases, uricases, such as uricase II (E.C.17.3.3),peptidases, different membrane proteins, amidohydrolases and variousgeneral stress proteins, being regarded as proof for the induction.

The present invention particularly relates to a method of findingcompounds which induce the transcription of the genes which code forplant-endogenous stress tolerance enzymes, which comprises:

-   -   a) exposing test plants to one or more abiotic stress factors,    -   b) bringing control plants, under otherwise identical conditions        like the test plants of a), additionally into contact with a        test compound, be it in the form of dressed seed material or be        it by spraying with a particular development stage or else by        uptake via the roots,    -   c) extracting RNA from the test plants and the control plants,    -   d) either labeling the RNA directly with a radiolabel or with a        cold label, or else labeling the RNA with a radiolabel or a cold        label while simultaneously transcribing it enzymatically into        the corresponding cDNA, or else transcribing the resulting,        unlabeled cDNA enzymatically into a corresponding radiolabeled        or cold-labeled cRNA,    -   e) hybridizing a DNA microarray which comprises plant DNA        sequences with the substances obtained in step d),    -   f) generating expression profiles of the genes for the        expression of different stress proteins by comparing the plants        tested in a) and b),    -   g) quantitatively determining the expression differentials        measured in f), and    -   h) carrying out the cluster analysis of the expression profiles        assigned in g) for a final classification.

In the case of the abovementioned step d), the enzymatic transcriptionof the resulting cDNA into a cRNA must be considered as the preferredprocess step since a further amplification of the hybridization samplecan thereby be achieved. Likewise preferred is labeling by means of coldnucleotides, especially preferably labeling by means of biotinylated UTPand/or CTP, where the detection is carried out after the hybridizationreaction by binding streptavidin-phycoerythrin as fluorophore to thebiotinylated cRNA. A detection of the specific phycoerythrinfluorescence, which serves as the base for the quantitativedetermination of the expression differentials measured, is carried outafter the hybridization step, with the aid of a laser scanner.

The present invention preferably relates to a process in which theabovementioned procedures a)-h) are maintained, where, in the case ofthe intended increase in the case of heat stress, the genes for theexpression of the cytochrome oxidases, such as cytochrome oxidase P450,glycosyltransferases, uricases, such as uricase II (E.C.17.3.3),peptidases, different membrane proteins, amidohydrolases in the case ofheat-stressed and non-heat-stressed plants is compared, preferably ofthe genes for the expression of “N-carbamyl-L-amino acid amidohydrolase”(Zm.11840.1.A1_at), of “serine carboxypeptidase (Zm.18994.2.A1_a_at), ofuricase II (E.C.1.7.3.3) and of glycosyltransferase(Zm.12587.1.S1_s_at), very especially preferably of the genes for theexpression of “N-carbamyl-L-amino acid amidohydrolase”(Zm.11840.1.A1_at) and of “serine carboxypeptidase” (Zm.18994.2.A1_a_at)(signature as per maize genome array from Affymetrix (Affymetrix Inc.,3380 Central Expressway, Santa Clara, Calif., USA)), and where the geneexpression in comparison with the heat-stressed control plant upontreatment with, is, for example, increased by a factor of 1.5 or more,preferably by a factor of 1.5 to 30, preferably 1.5 to 20, especiallypreferably 1.5 to 10, very especially preferably 1.5 to 5, where theincrease in the modified expression profiles of individual genesindependently of one another can be in the various ranges which havebeen mentioned above.

The present invention also preferably relates to a process in which theabovementioned process steps a)-h) are maintained, where, in the case ofthe intended increase in the case of drought stress for example thegenes for the expression of the late embryogenesis abundant proteinssuch as the dehydrins, of the universal stress protein (Zm.818.1.A1_at),non-symbiotic hemoglobin (Zm.485.1.A1_at), the protein which isaddressed as “Zm.818.2.A1_a_at” (maize genome array from Affymetrix(Affymetrix Inc., 3380 Central Expressway, Santa Clara, Calif., USA))and of the protein addressed as “Zm.18682.1.A1_s_at” (maize genome arrayfrom Affymetrix (Affymetrix Inc., 3380 Central Expressway, Santa Clara,Calif., USA)) of drought-stressed and non-drought-stressed plants iscompared, preferably the genes for the expression of the universalstress protein (Zm.818.1.A1_at), non-symbiotic hemoglobin(Zm.485.1.A1_at), of the protein addressed as “Zm.818.2.A1_a_at”(signature as per maize genome array from Affymetrix (Affymetrix Inc.,3380 Central Expressway, Santa Clara, Calif., USA)) and of the proteinaddressed as “Zm.18682.1.A1_s_at” (maize genome array from Affymetrix(Affymetrix Inc., 3380 Central Expressway, Santa Clara, Calif., USA))where the gene expression in comparison with the drought-stressedcontrol plant upon treatment with, is, for example, increased by afactor of 1.5 or more, preferably by a factor of 1.5 to 30, preferably1.5 to 20, especially preferably 1.5 to 10, very especially preferably1.5 to 8, where the increase in the modified expression profiles ofindividual genes independently of one another can be in the variousranges which have been mentioned above.

The present invention furthermore relates to the use of certain DNAmicroarrays which are used on the basis of genetic information fromplants, preferably genetic information from useful plants, especiallypreferably from useful plants such as, for example, from maize, cerealssuch as wheat, barley, rye, oats, rice and soya, preferably from maize,wheat, barley, rye, rice and soya, especially preferably from barley,maize, wheat, rice and soya, very especially preferably from maize,wheat and soya, for finding modified gene expression patterns. Here, therelative changes of the gene patterns for genes of different stressproteins in plants treated with test compounds are compared withuntreated control plants under otherwise identical stress conditions.

The invention furthermore relates to the use of the promoters of theindicator genes described in conjunction with specific reporter genes(for example GUS, GFP, luciferase and the like) for finding substanceswhich have a positive effect on the abiotic stress tolerance in cropplants. Here, transgenic test plants are generated which comprise theabovementioned promoter/reporter gene constructs. Active substanceswhich increase the abiotic stress tolerance of plants by theabove-described mechanism induce the expression of the reporter gene andcan be identified with the aid of a calorimetric, fluorimetric or othersuitable assay.

The invention furthermore relates to the use of the described indicatorgenes for increasing the abiotic stress tolerance in transgenic cropplants. Here, the genes are fused with a suitable promoter which has thedesired strength and specificity, and the constructs are transformedinto monocotyledonous or dicotyledonous crop plants. The resultingtransgenic plants are distinguished by an increased tolerance to abioticstress, for example chill, heat, drought and the like.

The present invention furthermore also relates to the use of thecompounds which have been identified with the aid of the DNA microarraytaking into consideration the expression profiles of the genes and/or ofcompounds which are already known as safeners and which, in the case ofabiotic stress conditions such as, for example, abiotic stress factorswhich act on this plant, such as temperature (chill, frost or heat),water (dryness or drought) or the chemical load (lack or excess ofmineral salts, heavy metals, gaseous noxious substances), have apositive effect, i.e. an expression-enhancing effect, with regard totheir inductive effect on single genes or a plurality of genes of theplant-endogenous defense mechanisms, such as, for example, in the caseof heat stress on cytochrome oxidases such as cytochrome oxidase P450,on glycosyltransferases, on uricases such as uricase II (E.C.17.3.3), onpeptidases, on different membrane proteins, on amidohydrolases and/orvarious stress proteins, and/or for example in the case of droughtstress have a positive effect, i.e. an expression-enhancing effect, withregard to their inductive effect on single genes or a plurality of genesof the universal stress proteins, non-symbiotic hemoglobin(Zm.485.1.A1_at), of the protein addressed as “Zm.818.2.A1_a_at” (maizegenome array from Affymetrix (Affymetrix Inc., 3380 Central Expressway,Santa Clara, Calif., USA)) and of the protein addressed as “Zm.18682.1.A1_s_at” (signature according to maize genome array fromAffymetrix (Affymetrix Inc., 3380 Central Expressway, Santa Clara,Calif., USA)), as active substances for increasing the stress tolerancein useful plants.

The invention also relates to the use of substances identified with theaid of the DNA microarray and of the molecules which are already knownas safeners for increasing the tolerance to abiotic stress factors invarious crop plants such as maize, cereals such as wheat, barley, rye,oats, rice and soya, preferably maize, wheat, barley, rye, rice andsoya, especially preferably maize, wheat, rice and soya, very especiallypreferably maize, wheat and soya.

The present invention therefore also relates to the use of the compoundswhich have been identified with the aid of the DNA microarray takinginto consideration the expression profiles of the genes and/or ofcompounds which are already known as safeners which, in plants, directlyor indirectly, for example via a signal transduction chain, contributeto increasing the tolerance to abiotic stress factors, such as, forexample, temperature (such as chill, frost or heat), water (such asdryness, drought or anoxia), or the chemical load (such as lack orexcess of mineral salts, heavy metals, gaseous noxious substances), forincreasing the yield, for extending the vegetation period, for makingpossible an earlier sowing date, for increasing the quality, or for usein plant breeding using otherwise less vital inbred lines.

The present invention therefore also relates to a method of increasingthe yield in crops of useful plants, for extending the vegetationperiod, for making possible an earlier sowing date, for increasing thequality, or for use in plant breeding using otherwise less vital inbredlines which comprises treating the useful plants by seed dressing, byfoliar sprays or by cell application with one or more compounds whichhave been identified with the aid of the DNA microarray and/or compoundswhich are already known as safeners.

Preferred in this context are those compounds whose use as what areknown as safeners is already known in crop protection, such as, forexample, from the group of the compounds known as safeners consisting ofthe compounds of the formulae I-1 (mefenpyr-diethyl), I-9(isoxadifen-ethyl), II-1 (chloquintocet-mexyl), b-11 (fenclorim), b-14(dymron), VIII-3(4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide),very especially preferably the compounds I-1 and VIII-3(4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide)).

By applying the abovementioned compounds individually or in combination,useful plants can be protected efficiently against the effects ofabiotic stress factors, which manifests itself for example in higheryields.

The present invention therefore also relates to a method of increasingthe tolerance of useful plants in crops of useful plants to abioticstress factors by the individual or combined application of thecompounds identified with the aid of the DNA microarray taking intoconsideration the expression profiles of the genes and/or of compoundswhich are already known as safeners.

The examples which follow describe the invention in detail.

EXAMPLE 1

Proof of the activity of safeners on plants which had been exposed tospecific drought-stress conditions, by means of gene expressionprofiling (GFP):

Abiotic Wtress Factor=Drought Stress

Maize seeds cv. Lorenzo were dressed with the compound4-cyclopropylamino-carbonyl-N-(2-methoxybenzoyl)benzenesulfonamide(=VIII-3). To this end, 10 g of seeds were incubated with 20 mg ofactive substance dissolved in 2 ml of methylene chloride, with gentleshaking, until the solvent had evaporated (approx. 30 minutes). Theseeds of the control group were only dressed with solvent. Thereafter,the treated seeds were placed into pots with compost (diameter: 10 cm,in each case 10 seeds per pot), and the maize seedlings were raised for10 days in a controlled-environment chamber under defined light,moisture and temperature conditions [white light, long day (16 hourslight, 8 hours dark), 70% atmospheric humidity, 24° C.]. In each case2×10 pots were used for the control groups and for the drought stressexperiment. While the plants were raised, they were watered from belowfor 20 minutes every 2 days by raising the water level in a tray. 10days after the seeds had germinated, the maize plants were exposed tothe drought stress. To this end, the plants of control group 1 (withoutdressing with active substance) and of the test group (with dressingwith active substance) were only irrigated every 7 days as describedabove. In the case of the plants of control group 2 (without dressingwith active substance) and of the test group 2 (with dressing withactive substance), the normal irrigation regime was reclaimed. After 3weeks of drought stress conditions, the experiment was evaluated asfollows. The aerial plant parts were cut off and dried overnight at 50°C. On the next day, the foliar biomass was determined in [g] (drymatter) per pot.

The data were averaged over the in each cae 10 pots of the plant group.The numerical values shown in table 1 are relative values in [%]relative to the data obtained with the control group 2 (without dressingwith active substance, normal irrigation regime). TABLE 1 Drought stressexperiment with maize plants without and with dressing with activesubstance Relative dry matter Plant group: Treatment: [%]: Control group1 −S/+D 50 Control group 2 −S/−D 100 Test group 1 +S/+D 80 Test group 2+S/−D 100S = compound VIII-3(=4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide),D = drought stress

Without stress conditions, the average dry matter is the same plantsfrom undressed seeds and from dressed seeds (control group 2, test group2).

On average, the plants from the group which had been dressed with thecompound VIII-3(=4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide)showed a more compact habit than the plants from the control groupwhich, however, had no effect on the dry matter. Under drought stress,however, the average foliar biomass (dry matter) of theactive-substance-dressed plants was significantly increased over theundressed control plant (control group 1, test group 1).

EXAMPLE 2

Abiotic Stress Factor=Heat Stress

Maize seeds cv. Lorenzo were dressed as in example 1 with the compound4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide(=VIII-3) or treated only with solvent without active substance. Theseedlings were raised for 10 days in the controlled-environment chamberunder defined conditions, likewise as described in example 1.2×10 potswith maize plants were used for the heat stress experiment. The controlgroup consisted of undressed plants (solvent), the test group of plantswhich had been dressed with active substance. To apply the heat stressconditions, both plant groups were placed for 2 days into acontrolled-environment cabinet at 45° C., white light, long day (16hours light, 8 hours dark) and 70% atmospheric humidity. To avoiddesiccation as the result of the high temperature, the plants wereirrigated once per day from below by raising the water level in a tray.After the heat stress, it was observed that—especially in the controlgroup—the shoots of many plants had collapsed and that the leaves werelying flat on the ground.

The experiment was valued quantitatively, taking into consideration thefollowing criteria.

After the heat treatment, the plants which had collapsed were countedand the result per pot was assessed:

<20% of the emerged plants collapsed: some damage ◯

20-50% of the emerged plants collapsed: medium damage

>50% of the emerged plants collapsed: severe damage ●

Thereafter, all plants were grown on for 2 weeks under standardconditions. Then, the length increment of the individual plants wasmeasured, and the survival rate of the plants per pot was determined:

>50% survival rate: some damage ◯

20-50% survival rate: medium damage

<20% survival rate: severe damage ●

The results of the evaluation of the experiment are compiled in table 2.

The undressed control plants were severely damaged by the heat stress.What was noticeable was in particular the collapse of the shoots in thecase of most plants and the poor survival rate. The test plants whichhad been dressed with active substance were distinguished in particularby considerably better “standing”. While the final score highlights thedamage caused by the severe heat stress even in those plants, theirsurvival rate was signficantly higher than in the control group. TABLE 2Dried-stress experiments with maize plants with or without dressing withactive substance Plant group: Treaetment: Control group −S/+H Interimscore (collapsed plants): ●●●●●●●◯◯◯ Final score (survival rate):●●●●●●●●●◯ Test group +S/+H Interim score (collapsed plants): ◯◯◯◯◯◯◯◯◯◯Final score (survival rate): ●●●●●

S = compound VIII-3(=4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide),H = heat stress

EXAMPLE 3

Abiotic Stress Factor=Chill Stress (Greenhouse).

Maize seeds cv. Lorenzo were sown into 10-cm-pots into compost at a rateof 10 seeds per pot. All experimental groups consisted of in each case 4pots. The sown seeds of test groups 1 and 2 were sprayed pre-emergencewith 50 and 100 [g a.i./ha], respectively, of the compound4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide(=VIII-3). The seeds of the control group remained untreated. The plantswere raised under controlled conditions in a controlled-environmentchamber [white light (long day: 16 h light, 8 h dark), 22° C. day-timetemperature, 14° C. night-time temperature, 60% atmospheric humidity].After germination, when the plants had attained a length of approx. 1cm, 2 pots from each group were incubated for 6 h in a differentcontrolled-environment chamber under chill-stress conditions at −2° C.Thereafter, these plants were returned to the others in the firstcontrolled-environment chamber.

After a further 24 hours under standard conditions, the experiment wasevaluated. It was observed that the chill stress caused chloroses at theleaf tips of the seedlings of the untreated control group. Thesesymptoms were either absent or only very weakly pronounced on the plantswhich had been treated with the active substance. None of the plantsfrom the test groups of the control group which had been keptexclusively under standard conditions without chill stress showed anydamage symptoms whatsoever.

To evaluate the experiment quantitatively, the plants with chloroses ofthe leaf tips were counted. The total number of the plants per testgroup and cold stress treatment was 20, provided over 2 pots in eachcase.

The results of the evaluation of the experiment are compiled in table 3.TABLE 3 Chill-stress experiment (greenhouse) with maize plants withoutand with treatment with the active substance, compound VIII-3(=4-cyclopropylaminocarbonyl-N-(2- methoxybenzoyl)benzenesulfonamide),pre-emergence. All plants were exposed to chill-stress treatment. Thetotal number of plants per group was 20. Treatment with active substance(pre- Number of damaged Plant group: emergence) [g a.i./ha]: plants(chloroses): Control group 0 9 Test group 1 50 1 Test group 2 100 0

The results demonstrate that the treatment with the active substanceVIII-3(=4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide) canmarkedly reduce the damage symptoms which are the result of chillstress, or, at the higher dosage rate, completely prevents theoccurrence of these symptoms.

EXAMPLE 4

Abiotic Stress Factor=Chill Stress (Field)

Maize seeds (dent corn) were dressed with 0.003 mg and 0.03 mg of thecompound4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide(=VIII-3) per g of seeds and sown into test plots, each of which measure34 m² in size. One control plant contains untreated seed. Approximately8 days after the seed emerged, the seedlings were in the one-leaf stageand were exposed for 5 days to the following temperature conditions:Maximum: Minimum: Day 1: 16.1° C. 7.2° C. Day 2: 17.8° C. 2.7° C. Day 3:16.7° C. 0.6° C. Day 4: 16.7° C. 1.1° C. Day 5: 22.8° C. 12.2° C. 

After this chill period, the test plots were scored. For this purpose,all plants were assessed individually, and plants with at least 20%chill symptoms based on the total leaf area (burns and/or chloroses)were considered to be damaged.

The results are compiled in table 4. In the control plot withoutdressing with active substance, all plants (100%) showed theabove-described chill symptoms. In the test plots with dressing withactive substance, the chill damage was significantly reduced.

Here, only approximately 12% of the plants showed damage symptoms. Themaximum frost-protection effect was attained in the range of the activesubstance quantities which had been used for the dressing, as shown inthe table. TABLE 4 Chill stress experiment (field) with maize plantswithout and with dressing with the active substance VIII-3(=4-cyclopropylaminocarbonyl-N-(2- methoxybenzoyl)benzenesulfonamide)Plant group: Chill damage [%]*: Untreated 100 Dressed with 0.003 mg of(VIII-3 = 4- 12 cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide) per seed Dressed with 0.03 mg VIII-3(=4- 12 cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide) per seed*Number of plants with chill damage >20% best of the total number ofplants in the test plot

EXAMPLE 5

Characterization of genes which are induced by test substances underabiotic stress conditions, measured by gene expression profiling (GEP):

Maize seeds cv. Lorenzo were dressed as described in example 1 with thecompound VIII-3(=4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide) orwith solvent. The plants were raised for 10 days in acontrolled-environment chamber (conditions: see example 1).

Thereafter, the plants were exposed to the following stress conditions:

-   -   (1) Heat stress: 6 h at 45° C.    -   (2) Drought stress: 7 days without irrigation, 24° C.

The control plants of the specific experimental group were kept underthe standard conditions described in example 1 (temperature,irrigation).

After the stress treatment, the leaves of the stressed plants and of theunstressed control plants were harvested, shock-frozen in liquidnitrogen and stored at −80° C. until processed. All experiments werecarried out in replications of in each case 2 pots.

The labeled RNA probes for the DNA chip hybridization were prepared asdescribed in the protocols (Expression Analysis, Technical Manual) fromAffymetrix (Affymetrix Inc., 3380 Central Expressway, Santa Clara,Calif., USA). First, total RNA was isolated from in each case 500 mg ofthe harvested leaves. In each case 10 μg of total RNA were used for thecDNA first- and second-strand synthesis. The cDNA was amplified with T7polymerase and simultaneously labeled with biotin-UTP. In each case 20μg of this biotinylated cDNA were employed for the hybridization of themaize genome array from Affymetrix. This DNA microarray contains DNAsequences whose totality represents 13339 genes. Thereafter, the DNAmicroarrays were washed in the Affymetrix Fluidics Station, stained withstreptavidin/phycoerythrin (Molecular Probes, P/N S-866) and scannedwith the appropriate Agilent Laser Scanner (Agilent Gene Array Scanner).The fluorescence data obtained were analyzed using Affymetrix'sMicroarray Suite 5 software. After the quality assurance had beenperformed, all DNA chip analyses were stored in a database. To determinerelevant expression values (induction factors, repression factors), theabsolute expression values of the genes from the respective stressexperiments were compared with the values of the respective controlexperiments (i.e. without abiotic stress and solvent-dressing only),based on the scoring function predetermined by the Affymetrix software.The resulting 4 expression values per gene were averaged by calculatingthe median value. These median values are shown in the results tables asinduction factors. Similarity comparisons of expression profiles ofvarious experiments and cluster analyses were carried out using the“genedata expressionist” software from Genedata (Genedata, Maulbeerstr.46, CH-4016 Basel, Switzerland).

The analysis of the expression profiles specifically searched for geneswhich are induced by the test substances only in conjunction withabiotic stress, but not by the substances or by stress alone. Such genescan be considered as indicators for additional anti-stress effects ofthe substances which exceed the known safener effect. The results fromthe analyses are shown in the tables which follow. The inductionpatterns of the indicator genes described permit the targeted finding ofactive substances for increasing the abiotic stress tolerance in cropplants.

-   a) Under heat stress conditions, i.e. the tested maize plants    (dressed with 2 mg a.i.    4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide/g    seeds) were exposed to a temperature of 45° C. for 6 hours 7 days    after germination.

An overview over the induced gene groups revealed the following pattern,which is shown in table 5: TABLE 5 Sample Set No. Condition A ConditionB Condition C Zm.11840.1.A1_at 1.74 1.75 4.10 Zm.4274.1.S1_at 1.32 1.221.93 Zm.3040.1.S1_at 1.52 1.33 2.48 Zm12587.1.S1.s_at 1.30 1.45 2.33Zm18994.2.A1_a_at 1.16 1.46 2.66 Zm.13498.1.S1_at 2.56 1.73 4.45

The respective sample set no. corresponds to:

Zm.11840.1.A1_at: putative N-carbamyl-L-amino acid amidohydrolase

Zm.4274.1.S1_at: cytochrome P450

Zm.3040.1.S1_at uricase 11 (E.C.1.7.3.3); nodule specific uricase

Zm12587.1.S1.s_at: glycosyltransferase

Zm18994.2.A1_a_at: putative serine transferase

Zm.13498.1.S1_at: membrane protein

-   Condition A: heat stress (6 hours, 45° C.)-   Condition B: Seeds dressed with    4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide    (VIII-3)/NO heat stress-   Condition C: Seeds dressed with    4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide    (VIII-3)+heat stress (6 hours, 45° C.).

Ignoring a slight basal induction of the analyzed gene activities, apronounced increase in the gene expression was observed in all cases andis, in the case of the genes mentioned here, in the range of from 1.5 to2.35 (expression under condition C/expression under condition A). If thetest compound VIII-3 was tested on its own, i.e. without heat stress,the measured expression levels were in the range of the range induced byheat stress, or below or slightly above the range induced by heatstress.

The induction patterns derived from table 5 and which are shown directlyby the resulting expression values show characteristic inductions by theaction of the compound4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide(=VIII-3), the effect on the putative N-carbamyl-L-amino acidamidohydrolase [Zm.11840.1.A1_at] and on the putative serinecarboxypeptidase [Zm18994.2.A1_-at] being most pronounced.

-   b) Under dried stress conditions, i.e. the tested maize plants    (dressed with 2 mg a.i.    4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide/g    seeds) were exposed to a temperature of 24° C. for 7 hours 7 days    after germination.

An overview over the induced gene groups revealed the following pattern,which is shown in table 6: TABLE 6 Sample Set No. Condition A ConditionB Condition C Zm.818.1.A1_at 1.06 1.12 8.47 Zm.3633.4.A1_at 1.12 0.743.03 Zm.18273.1.S1_at 1.66 0.95 2.91 Zm.13229.1.S1_at 1.55 1.02 3.39Zm.12035.1.A1_at 1.86 0.90 3.66 Zm.485.1.A1_at 0.89 1.00 5.49Zm.818.2.A1_at 0.93 1.10 5.40 Zm.10097.1.A1_at 1.23 1.27 3.29Zm.18682.1.A1_at 1.25 1.12 4.19

The respective sample set no. corresponds to:

Zm.818.1.A1_at universal stress protein

Zm.3633.4.A1_at wound induced protein (fragment)

Zm.18273.1.S1_at regulatory protein-like

Zm.13229.1.S1_at NBS-LRR type disease resistance protein O2 (fragment)

Zm.12035.1.A1_at similar to AT3G10120

Zm.485.1.A1_at non-symbiotic hemoglobin (HBT) (ZEAMP GLB1)

Zm.818.2.A1_at expressed protein

Zm.10097.1.A1_at expressed protein

Zm.18682.1.A1_at unknown protein

-   Condition A: drought stress (7 days, 24° C.)-   Condition B: Seeds dressed with    4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide    (VIII-3)/NO drought stress-   Condition C: Seeds dressed with    4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide    (VIII-3)+drought stress (7 days, 24° C.).

Ignoring a slight basal induction of the analyzed gene activities, apronounced increase in the gene expression was observed in all cases andis, in the case of the genes mentioned here, in the range of from 1.75to 8.0 (expression under condition C/expression under condition A). Ifthe test compound VIII-3 was tested on its own, i.e. without heatstress, the measured expression levels were in the range of the rangeinduced by dried stress, or in some cases even below the expression ofunstressed plants (at values <1.0).

The induction patterns derived from table 6 and which are shown directlyby the resulting expression values show characteristic inductions in thepreence of the compound4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide, theeffect on the universal stress protein [Zm.818.1A1_at] and non-symbiotichemoglobin (HBT) (ZEAMP GLB1) [Zm.485.1A1_at] being most pronounced.

1. A method of finding a compound which increases the tolerance toabiotic stress factors in plants, where the increase in thetranscription or expression of individual plant-endogenous genes or of aplurality of plant-endogenous genes is regarded as proof for theinduction.
 2. The method as claimed in claim 1, wherein theplant-endogenous genes are selected from the group of genes coding forproteins from the group of the cytochrome oxidases,glycosyltransferases, uricases, peptidases, various membrane proteins,amidohydrolases, late embryogenesis abundant proteins, and variousgeneral stress proteins.
 3. The method according to claim 1, whichcomprises: a) exposing test plants to one or more abiotic stressfactors, b) bringing control plants, under otherwise identicalconditions like the test plants of a), additionally into contact with atest compound, be it in the form of dressed seed material or be it byspraying with a particular development stage or else by uptake via theroots, c) extracting RNA from the test plants and the control plants, d)either labeling the RNA directly with a radiolabel or with a cold label,or else labeling the RNA with a radiolabel or a cold label whilesimultaneously transcribing it enzymatically into the correspondingcDNA, or else transcribing the resulting, unlabeled cDNA enzymaticallyinto a corresponding radiolabeled or cold-labeled cRNA, e) hybridizing aDNA microarray which comprises plant DNA sequences with the substancesobtained in step d), f) generating expression profiles of the genes forthe expression of different stress proteins by comparing the plantstested in a) and b), g) quantitatively determining the expressiondifferentials measured in f), and h) carrying out the cluster analysisof the expression profiles assigned in g) for a final classification. 4.The method as claimed in claim 3, where, in the case of the intendedincrease of the tolerance under heat stress conditions, the expressionof the genes of the cytochrome oxidases, such as the cytochrome oxidaseP450, glycosyltransferases, uricases, peptidases, various membraneproteins, amidohydrolases, is compared for heat-stressed andnon-heat-stressed plants.
 5. The method as claimed in claim 4, whereinthe expression of the genes of the N-carbamyl-L-amino acidamidohydrolase, the serine carboxypeptidase, the uricase II(E.C.1.7.3.3) and the glycosyltransferase is compared for heat-stressedand non-heat-stressed plants.
 6. The method according to claim 4,wherein the expression profile of one or more of the abovementionedgenes is increased by a factor of 1.5 to 30, preferably 1.5 to 20,especially preferably 1.5 to 10, very especially preferably 1.5 to
 5. 7.The method according to claim 3, where, in the case of the intendedincrease of the tolerance under drought stress conditions, theexpression of the late embryogenesis abundant proteins, of the universalstress protein, of the non-symbiotic hemoglobin (Zm.485.1.A1_at), of theprotein addressed as “Zm.818.2.A1_a at” (signature according to maizegenome array from Affymetrix) and of the protein addressed as“Zm.18682.1.A1_s_at” (signature according to maize genome array fromAffymetrix) of drought-stressed and non-drought-stressed plants iscompared.
 8. The method according to claim 7, wherein the expression ofthe genes of the universal stress protein (Zm.818,1.A1_at), of thenon-symbiotic hemoglobin (Zm.485.1.A1_at) of the protein addressed as“Zm.818.2.A1_a_at” (signature according to maize genome array fromAffymetrix) and of the protein addressed as “Zm.18682.1.A1_s_at”(signature according to maize genome array from Affymetrix) ofdrought-stressed and non-drought-stressed plants is compared.
 9. Themethod according to claim 7, wherein the expression profile of one ormore of the abovementioned genes is increased by a factor of 1.5 to 30,preferably 1.5 to 20, especially preferably 1.5 to 10, very especially1.5 to
 8. 10. The use of one or more compounds which are identified withthe aid of a method as claimed in claim 1 and/or compounds which arealready known as safeners, for increasing the tolerance to abioticstress factors, for increasing the yield, for extending the vegetationperiod, for making possible an earlier sowing date, for increasing thequality, or for use in plant breeding using otherwise less vital inbredlines.
 11. The use of compounds as claimed in claim 10 whose use assafeners is already known in crop protection, selected from the groupconsisting of mefenpyr-diethyl, isoxadifen-ethyl, chloquintocet-mexyl,fenclorim, dymron and4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide. 12.The use of compounds as claimed in claim 11 whose use as safeners isalready known in crop protection, selected from the group consisting ofmefenpyr-diethyl and4-cyclopropylaminocarbonyl-N-(2-methoxybenzoyl)benzenesulfonamide. 13.The use of compounds as claimed in claim 10 for increasing the toleranceto abiotic stress factors in the crop plants maize, wheat, barley, rye,oats, rice, soya, sunflower, oilseed rape and sugar beet.
 14. A methodof increasing the yield in crops of useful plants, which comprisestreating the useful plants by seed dressing, by foliar sprays or by soilapplication, with one or more compounds which have been identified by amethod as claimed in claim 1 and/or compounds which are already known assafeners in crop protection.
 15. A method of extending the vegetationperiod in crops of useful plants, which comprises treating the usefulplants by seed dressing, by foliar sprays or by soil application, withone or more compounds which have been identified by a method as claimedin claim 1 and/or compounds which are already known as safeners in cropprotection.
 16. A method of making possible an earlier sowing date incrops of useful plants, which comprises treating the useful plants byseed dressing, by foliar sprays or by soil application, with one or morecompounds which have been identified by a method as claimed in claim 1and/or compounds which are already known as safeners in crop protection.17. A method of increasing the quality in crops of useful plants, whichcomprises treating the useful plants by seed dressing, by foliar spraysor by soil application, with one or more compounds which have beenidentified by a method as claimed in claim 1 and/or compounds which arealready known as safeners in crop protection.